Scratch building a roll cage

[Grumpy Modeller]

Hi,

 

I'm looking to scratch build a roll cage for my model car but I'm not sure how to go about it as I've never done any scratch building before.

 

What materials am I best using ?

 

Are there any good tutorials that could help ?

 

Any advise would be much appreciated

 

Cheers,
Simon

 

 

[albergman]

Simon

 

A roll cage is a nice subject to scratch build as it's a fairly simple shape  with mostly right angles.     I would suggest doing it with brass rod of a suitable thickness for the scale of car you're building and most hobby shops carry it.    Brass tube is also available but it won't bend properly but rod can quite easily be bent to shape.

I don't know how complex a shape you want but for a  bras cage you'll definitely be needing to solder it together.

 

I've  seen something similar done using leftover sprue from a kit.    If you can find some of a suitable scale sandpaper or file off all remnants and see if you can fabricate what you need.

 

Hope this helps

 

Frank

 

 

[shood23]

Evergreen plastic rod (not tube as it may buckle in the bends) heated in hot water if you need to bend it. A thin round file so you can make the joins between 2 bits look proper and finally as many reference pictures of the style of cage you want so you know how much/ where to bend bits and where other bits should go. Oh and lots of patiance as the chances are you won't get some bits right the first time. 

 

Shaun 

[mbdesignart]

Or for the best of both worlds, try this  http://www.ema-models.co.uk/index.php/coloured-butyrate-tube-fittings.html   'plastic' rod with a brass insert.  Cut the brass insert short where butt jointing to enable you to round off as Shaun suggests and it's easy to bend, use EMA Plastic Weld adhesive. No soldering if you haven't the skill set.  Raboesch do plastic rod too in 1m lengths for around £1.50, depending on diameter.

[PatW]

I've built a lot of these using plastic rod just from the sprues you get in the kits. I've initially got my info from looking at race touring/rally car rollcages on Google search. Clean up the sprue with a light file, I bend using a small night light type candle, or by using a small round file to cut slots at the end of each piece to get of the joints at the correct angles. Also see if they have any YouTube video's on the subject, it covers most things. 

There are also quite a few internet model stores that sell kits to just glue together.

[keefr22]

On 11/07/2017 at 1:10 PM, albergman said:

Brass tube is also available but it won't bend properly

 

If you insert brass rod which has an external diameter the same as the inside diameter of the tube, the latter will bend much more cleanly. It also helps to anneal the tube & rod (heat them to cherry red then immediately plunge them into cold water)  in the area of the bend.

 

But I also prefer to use plastic which I find much easier to work with, but I tend to use tube, again with a suitable diameter of brass rod inserted which again makes it easier to bend.

 

Keith 

[Black Knight]

What about using thick copper wire from heavy duty cable.

I have thicknesses up to 3mm diameter. All gleaned from scrap left over from street lighting and house/factory rewiring.

Once bent the pieces can be easily soldered together

[griffsrw]

all good advice from the previous replies, its just picking a method that suits yourself. i have used evergreen type 1.6mm diameter round and find it much easier to adjust the fit. it is readily available on ebay. i have also used copper wire as black knight suggests, i use the earth from 2.5mm flat power cable. annealed as per keefr 22 recommends. another tip you could try is instead of using the floor of your model to build up your cage, why not use a piece of wood instead, just for the main cage, when you are happy with the fit, then transfer it to the model to add further components. good luck, i think you will find building a cage from scratch very rewarding.

[Rob de Bie]

On 7/11/2017 at 11:50 AM, Grumpy Modeller said:

I'm looking to scratch build a roll cage for my model car but I'm not sure how to go about it as I've never done any scratch building before.

 

What materials am I best using ?

 

Are there any good tutorials that could help ?

 

Any advise would be much appreciated

Maybe some tips on the build sequence, based on the single roll cage that I've partly built so far. I used 2 mm polystyrene tube with brass wire inside, otherwise the bends will not stay in the plastic.

 

I started with the main hoop. That can be lot of work to make fit properly, since it needs to fit tightly against the roof and the B-pillars. I think I test-fitted it two dozen times. And then I bent a fresh one because the first one was a bit worn out. Next were the two stays to the rear. That way you stabilise the main hoop nicely, giving you a solid base.

 

 

The third part was the roof hoop. Not all cars are built like this, in some the A-pillar tubes run all the way to the main hoop. Since the roof hoop cannot float free, I installed some temporary braces. The fourth part consisted of the A-pillar tubes. They were very difficult for this car, and the one in the photo is not the definitive one. I even had to build more temporary braces / jigs. Turns out those A-pillar tubes required another bend near the roof hoop.

 

 

That's how far I got. It can be a lot of work, but it is fun to do.

 

Looking at other scratch-built roll cages, I often see tubing that is too thick, and that makes it look like a toy. In this case I found out the correct diameter in the class rules from that era. Another thing I notice often is that the roof tubes are set too low, so they are very visible through the windows. On real cars this is usually not the case.

 

Good luck with your project!

 

Rob

 

Edited August 13, 2017 by Rob de Bie